Recently, Lin Yuan had been doing all he could to collect spirit qi crystals. Morbius had also absorbed its World Grace during its evolution to Myth Breed. As a result, Lin Yuan possessed an astonishing store of spirit qi crystals.
Since Lin Yuan did not have many opportunities to use these spirit qi crystals, he decided to use some to evolve Green Vine.
Green Vine had already been evolved to Sovereign/Immortal III. It was the strongest combatant Lin Yuan possessed that he had evolved through spirit qi crystals.
Rather than letting the spirit qi crystals sit in storage, it would be better to put them to use.
Feys that had reached Sovereign/Immortal were very foreign to Lin Yuan. He had not yet had the chance to interact with feys of such level.
He did have experts under him who possessed feys of such a level and had helped them to evolve said feys.